removing flakyness in unit test

openassessment/xblock/test/test_submission.py

@@ -202,7 +202,6 @@ class SubmissionTest(XBlockHandlerTestCase):
     @scenario('data/file_upload_scenario.xml')
     def test_remove_all_uploaded_files(self, xblock):
         """ Test remove all user files """
-        self.maxDiff = None
         s3 = boto3.resource('s3')
         s3.create_bucket(Bucket='mybucket')
         s3.Object('mybucket', 'submissions_attachments/test_student/test_course/' + xblock.scope_ids.usage_id).put(
@@ -216,7 +215,7 @@ class SubmissionTest(XBlockHandlerTestCase):
         download_url = api.get_download_url("test_student/test_course/" + xblock.scope_ids.usage_id)
         resp = self.request(xblock, 'download_url', json.dumps(dict()), response_format='json')
         self.assertTrue(resp['success'])
-        self.assertEqual(download_url, resp['url'])
+        self.assertTrue(resp['url'].startswith(download_url))
 
         resp = self.request(xblock, 'remove_all_uploaded_files', json.dumps(dict()), response_format='json')
         self.assertTrue(resp['success'])